In computer networks, it is advantageous to ascertain the health of a client computer before allowing the client to access the network. By determining that the client computer is compliant with network health policy standards, for example by having the latest antivirus software or a properly installed firewall, the risk to the network can be minimized. If it is determined that a client computer does not comply with administrator-defined network health policy standards, it can be desirable to restrict access to the network until such time as the client becomes compliant with the standards.
When a client connects to a network, different enforcement methods can be used to ensure compliance with network health policy standards. These enforcement methods can include the use of 802.1X authenticating devices, Internet Protocol security policies (IPsec) and the Dynamic Host Configuration Protocol (DHCP). For IPv4 networks, DHCP can be used to control client computer access to a network through the routes and default gateway allocated by the DHCP server to the client. The routes and gateway can be modified by the DHCP server to restrict a non-compliant client's access to the network.